include/linux/bpfptr.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /* A pointer that can point to either kernel or userspace memory. */
   3 #ifndef _LINUX_BPFPTR_H
   4 #define _LINUX_BPFPTR_H
   5
   6 #include <linux/sockptr.h>
   7
   8 typedef sockptr_t bpfptr_t;
   9
  10 static inline bool bpfptr_is_kernel(bpfptr_t bpfptr)
  11 {
  12         return bpfptr.is_kernel;
  13 }
  14
  15 static inline bpfptr_t KERNEL_BPFPTR(void *p)
  16 {
  17         return (bpfptr_t) { .kernel = p, .is_kernel = true };
  18 }
  19
  20 static inline bpfptr_t USER_BPFPTR(void __user *p)
  21 {
  22         return (bpfptr_t) { .user = p };
  23 }
  24
  25 static inline bpfptr_t make_bpfptr(u64 addr, bool is_kernel)
  26 {
  27         if (is_kernel)
  28                 return KERNEL_BPFPTR((void*) (uintptr_t) addr);
  29         else
  30                 return USER_BPFPTR(u64_to_user_ptr(addr));
  31 }
  32
  33 static inline bool bpfptr_is_null(bpfptr_t bpfptr)
  34 {
  35         if (bpfptr_is_kernel(bpfptr))
  36                 return !bpfptr.kernel;
  37         return !bpfptr.user;
  38 }
  39
  40 static inline void bpfptr_add(bpfptr_t *bpfptr, size_t val)
  41 {
  42         if (bpfptr_is_kernel(*bpfptr))
  43                 bpfptr->kernel += val;
  44         else
  45                 bpfptr->user += val;
  46 }
  47
  48 static inline int copy_from_bpfptr_offset(void *dst, bpfptr_t src,
  49                                           size_t offset, size_t size)
  50 {
  51         return copy_from_sockptr_offset(dst, (sockptr_t) src, offset, size);
  52 }
  53
  54 static inline int copy_from_bpfptr(void *dst, bpfptr_t src, size_t size)
  55 {
  56         return copy_from_bpfptr_offset(dst, src, 0, size);
  57 }
  58
  59 static inline int copy_to_bpfptr_offset(bpfptr_t dst, size_t offset,
  60                                         const void *src, size_t size)
  61 {
  62         return copy_to_sockptr_offset((sockptr_t) dst, offset, src, size);
  63 }
  64
  65 static inline void *kvmemdup_bpfptr(bpfptr_t src, size_t len)
  66 {
  67         void *p = kvmalloc(len, GFP_USER | __GFP_NOWARN);
  68
  69         if (!p)
  70                 return ERR_PTR(-ENOMEM);
  71         if (copy_from_bpfptr(p, src, len)) {
  72                 kvfree(p);
  73                 return ERR_PTR(-EFAULT);
  74         }
  75         return p;
  76 }
  77
  78 static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
  79 {
  80         return strncpy_from_sockptr(dst, (sockptr_t) src, count);
  81 }
  82
  83 #endif /* _LINUX_BPFPTR_H */